Constant pressure, variable flow nozzle

ABSTRACT

A constant pressure, variable flow nozzle is disclosed wherein a flow restricting baffle is automatically positioned by hydraulic means so as to pass only that flow which can be provided at the desired pressure, thereby maintaining effective reach and penetration characteristics of the stream from the nozzle, despite variations in supply. The nozzle contains a hydraulically controlled baffle and is particularly useful as a fire fighting device.

United States Paten [151 3,684,192

McMillan 1451 Aug. 15, 1972 [54] CONSTANT PRESSURE, VARIABLE 2,554,409 5/l95l Holder ..239/452 FLOW NOZZLE 2,582,527 I l/l952 Burnett ..-...239/452 Inventor: H. McMillan, Hobart, I Allenbaugh X [73] Assignee: Fire Task Force Innovations, lnc., Primmy d L Ki Hobart, 1nd. AttorneyMerriam, Marshall, Shapiro & Klose [22] Filed: June 22, 1970 [57] ABSTRACT [2l] Appl. No.: 48,279

A constant pressure, variable flow nozzle 18 disclosed wherein a flow restricting baffle is automatically posi- [52] US. Cl .,239/452, 239/456 tioned by hydraulic means so as to pass-only that flow [5 l ll!!- Ci. ..B05b 1/32 which can be provided at the desired pressure, thereby Field Of Search 453, 456, maintaining effectivs reach and penetration charac 56 R f Ct d teristics of the stream from the nozzle, despite varia- 1 eerences le tions in supply. The nozzle contains a hydraulically UNITED STATES PATENTS controlled bafi'le and is particularly useful as a fire fighting device. 3,539,112 ll/l970 Thompson ..239/452 2 2,568,429 9/1951 Bumam et al. ..239/452 8 Claims, 2 Drawing Figures I L [7 2 I I I00 I00 I00 I 3 l 7 5 l5 /0 L /0a y a PATENTED I97? 3, 6 84, l 92 INVENTOR BY 2 ydejzzgg ffi W l 779 ATTORNEYS CONSTANT PREQSURE, VARIABLE FLOW NOZZLE The present invention concerns an improved nozzle. In general, it relates toa constant pressure, variable flow nozzle. More particularly, it concerns a nozzle which contains a hydraulically controlled baffle.

I-Ieretofore, various types of nozzles have been employed in combination with other fire fighting equipment to supply water for fighting fires. Variations or changes in the water supply conditions encountered in fighting fires present problems in proper nozzle selection. The water supply available for fighting one fire may be materially different from the water supply available for fighting another fire. For example, in some instances, an ample amount of water under sufficient pressure is available. In other instances only a very limited amount of water is available. In addition, changes in water supply conditions often occur during the course of fighting any particular fire. These latter changes may be caused, for example, by the use of additional fire fighting streams during the course of fighting a fire or by equipment malfunctions such as pumper failure, hose breakage, and the like.

It is important that the nozzles employed with fire fighting equipment be capable of providing satisfactory streams of water even under the varying or changing water supply conditions referred to above. Moreover, it is highly desirable that such nozzles do so automatically, that is, without the necessity for manual adjustment by an operator. Nozzles which do not require manual adjustment by an operator are particularly desirable since such nozzles obviate problems created by operator error or inability due, for example, to poor visibility, etc.

The present invention provides an improved constant pressure, variable flow nozzle eminently suitable for use with fire fighting equipment. The noule of the present invention provides a satisfactory stream of water even under water supply conditions heretofore considered as incapable of supplying a satisfactory stream. The nozzle of the present invention provides full utilization of available water supply and automatically compensates for changes occurring in water supply or elevation of nozzle during use. Moreover, the present nozzle automatically provides capabilities heretofore realized only by an operators correct manual usage of several different size nozzles.

The present invention will now be described by reference to the accompanying drawings.

FIG. 1 is a half sectional view of a noule of the present invention in minimum flow configuration;

FIG. 2 is a similar half section showing the nozzle in normal operating configuration.

The nozzle of the present invention comprises a nozzle body 12 provided with baffle-piston l and cylinder 2. Nozzle body 12, per se, forms no basis of the present invention. Nozzle body 12 comprises a fluid conduit through which fluid flows from left to right as the nozzle is shown in FIG. 1 and FIG. 2.

Nozzle body 12 may be, for example, a so-called constant gallonage fog nozzle body presently available from Elkhart Brass Mfg. Co., Inc., Elkhart, Ind. or Akron Brass Mfg. Co., Inc., Wooster, Ohio. Constant gallonage" nozzles have the capability of changing the shape or pattern (e.g., from straight-stream to fog pattern) of the stream exiting from the nozzle without changing the flow rate. With such a nozzle, however, flow rate does change considerably with change in pressure.

Cylinder 2 containing baffle-piston l is attached to nozzle body 12 by stem 10. A' first stem end 100 is threadably attached to acorn nut 11. A first intermediate section 100 of stem 10 between stem end 10a and truncated conical section 10d is supported by integral support 12a of nozzle body 12. A second stem end 10b is threadably attached to cylinder 2. A second intermediate section 10e of stem 10 located between truncated conical section 10d and stem end 10b is provided with baffle-piston l, which slides on stem section 10c with a close clearance fit.

Cylinder 2 contains integral valve means 2a located about the axis of cylinder 2. Integral valve means 20 comprises fluid passage 3, valve seat 4, valve ball 5, spacer 6, valve control spring 7 and adjusting screw 8, containing relief passage 9.

Baffle-piston 1 slides within cylinder 2. O-ring 13 provides a hydraulic seal between baffle-piston 1 and cylinder 2. Spring end 14a of return spring 14 may be seated in annular spring seat 19 in cylinder 2. Return spring 14 urges bafile-piston l to slide away from cylinder 2 (to the left as shown in the drawings).

Baffle-piston 1 comprises exterior surface or-face l6 and opposing interior surfaces 17. One or more orifices 15 in bafi'le-piston 1 provide means for communicating flow and pressure into cylinder 2. The bulk of fluid entering nozzle body 12 exits from the nozzle by means of annular opening 18 between nozzle body 12 and exterior face 16. The quantity of flow from the nozzle is determined by the size of annular opening 18. In the embodiment of the present invention illustrated in FIG. 1 the minimum size of annular opening 18 is determined by the position at which baffle-piston 1 seats, i.e. moves to the left as far as possible. Baffle-piston 1 seats when it slides into contact with truncated conical section 10d. In other embodiments (not shown) the bafflepiston can be arranged to seat in such a manner that no annular opening is provided until the pressure tends to exceed the predetermined operating pressure of the nozzle.

The operation of the nozzle of the present invention will now be described. At the start of operation water, for example, enters the nozzle at a pressure, for example, of psig which is below the predetermined operating pressure range, for example, -405 psig, of the male. Under these conditions, a limited amount of water flows out of the nozzle through annular opening 18 and also flows via orifices 15 into the cylinder 2. Pressure within noule body 12 and cylinder 2 becomes equalized and remains so as long as integral valve 2a remains closed. The interior, surfaces 17 of bafflepiston l are greater in projected, or effective area than the efi'ective area of exterior face 16 of baffle-piston l,

by an amount equal to the area of annular face 16a, which is exposed only to atmospheric pressure. As a result, a net force is exerted to the left (as shown in the drawings) on baffle-piston 1. This force, assisted by spring 14, retains baffle-piston l in a minimum opening position. The pressure at which integral valve 2a opens is predetermined and set by adjusting screw 8 acting through control spring 7 and valve spacer 6 on valve ball 5.

When water pressure furnished nozzle body 12 is increased to the point where the pressure tends to exceed the predetermined operating pressure of the nozzle, such pressure is transmitted through orifices 15 into cylinder 2 where it acts upon integral valve 2a causing valve ball 5 to unseat from valve seat 4. This latter action permits water to How out relief passage 9. Since the flow capability of integral valve 2a is designed to exceed the flow capability of orifices l5, pressure within cylinder 2 is maintained at the desired level by flow through integral valve 2a out relief passage 9. Under these conditions, the increased pressure within the nozzle body 12 tends to create a force on the effec tive area of exterior face 16 of the battle-piston l which exceeds the opposing force on the interior surfaces 17. Thus, baflIe-piston 1 moves to the right (as shown in the drawings) thereby increasing the size of annular opening 18. The increased size of annular opening 18 permits'a greater quantity of flow through the nozzle. Increased flow through the nozzle tends to reduce the pressure within the nozzle body 12 as a result of the increased friction losses within the nozzle supply system, e.g., hose lines and piping. Thus, provided the pressure at the source of supply exceeds the minimum operating pressure of the nozzle, a steady state flow condition is quickly realized for any flow rate within the operating range of the nozzle.

As supply pressure and flow are further increased, the nozzle of the present invention approaches the operating state illustrated in FIG. 2. Increased supply pressure and flow move the baffle-piston l to the right within cylinder 2, thus increasing the size of annular 4 opening 18. Water from cylinder 2 is relieved at an ap-' propriate rate by integral valve 20 to compensate for increased flowtransmitted to cylinder 2 through orifices 15. Water exiting from integral valve 2a through relief passage 9 is introduced into the center of the stream produced by the nozzle and is carried away by the stream.

When water supply pressure and flow are reduced, the action of the nozzle and the direction of travel of baffle-piston 1 are reversed. Under such conditions,

movable baffle-piston l closes to maintain the desired predetermined operating pressure.

It is apparent from the above that the action of the nozzle of the present invention is fully automatic and is such as to maintain an essentially constant nozzle operating pressure independent of variations in supply, provided supply pressure exceeds a predetermined minimum nozzle operating pressure.

It should also be apparent that the predetermined nozzle operating pressure may be set or determined by resetting a single screw adjustment. The sensitivity of the integral valve may be altered by changing the valve spring to provide, for example, either a more narrow or, on the other hand, a greater operating pressure range for the nozzle.

Nozzles of the present invention have been successfully operated to produce satisfactory streams, both straightstream and fog patterns, where the predetermined nozzle operating pressure was IOO psig (:55 psig) and the water supply rates to the nozzle varied from as little as 125 gallons per minute to as much as 1,200 gallons per minute.

FIG. 1 and FIG. 2 illustrate a preferred embodiment of the present invention in which the baffle-piston has stream shaping characteristics which reduce turbulence within the nonle. In addition, in the preferred embodiment illustrated an acorn nut is used to help distribute flow smoothly around the baffle support and the tective coatings. In addition, the integral valve employed may use positioning and retaining means other than an adjusting screw to locate and retain the valve spring and its related parts. Moreover, while the nozzle of the present invention has been described particularly I with reference to' its use with water for fire fighting purposes, it is apparent that the nozzle may find utility with fluids other than water and forpurposes other than fire fighting. v

Modifications within the spirit and scope of the present invention as defined by the appended claims are intended to be included.

What is claimed is:

1. An improved nozzle comprising a nozzle body, hydraulic means including a cylinder containing a moveable bafiIe-piston provided with orifice means, said hydraulic means being adapted to adjust automatically the position of said baffle-piston in said cylinder and with respect to said nozzle body creating a dynamic equilibrium in response to fluid quantity and pressure supplied said nozzle, to thereby provide nozzle pressure maintained at a predetermined, substantially constant level.

2. The nozzle of claim 1 wherein said baffle comprises a face exterior to said cylinder and faces interior to said cylinder, said interior faces having a combined effective surface area greater than the effective surface area of said exterior face.

3. The nozzle of claim 2 wherein said baffle is provided with orifice means providing fluid passageway between said exterior and interior faces.

4. The nozzle of claim 1 wherein said cylinder is provided with integral valve means adapted to relieve said cylinder so as to maintain pressure in said cylinder within a predetermined pressure range.

5. The nozzle of claim 4 wherein said valve means include adjustable screw means for setting said predetermined pressure range.

6. The nozzle of claim 3 wherein the flow capability through said orifice means is exceeded by the flow capability of the integral valve means defined in claim 7. A fire nozzle comprising a nozzle body including a fluid conduit;

a stem, one end of said stem being attached to said noule body and the other end being attached to a cylinder;

a movable baffle-piston adapted to slide within said cylinder and along a section of said stem;

orifice means in said baffle-piston providing a passageway for fluid to flow from said fluid conduit into said cylinder;

hydraulic valve means adapted to permit fluid to flow out from said cylinder when the pressure within said cylinder tends to exceed predetermined pressure; 

1. An improved nozzle comprising a nozzle body, hydraulic means including a cylinder containing a moveable baffle-piston provided with orifice means, said hydraulic means being adapted to adjust automatically the position of said baffle-piston in said cylinder and with respect to said nozzle body creating a dynamic equilibrium in response to fluid quantity and pressure supplied said nozzle, to thereby provide nozzle pressure maintained at a predetermined, substantially constant level.
 2. The nozzle of claim 1 wherein said baffle comprises a face exterior to said cylinder and faces interior to said cylinder, said interior faces having a combined effective surface area greater than the effective surface area of said exterior face.
 3. The nozzle of claim 2 wherein said baffle is provided with orifice means providing fluid passageway between said exterior and interior faces.
 4. The nozzle of claim 1 wherein said cylinder is provided with integral valve means adapted to relieve said cylinder so as to maintain pressure in said cylinder within a predetermined pressure range.
 5. The nozzle of claim 4 wherein said valve means include adjustable screw means for setting said predetermined pressure range.
 6. The nozzle of claim 3 wherein the flow capability through said orifice means is exceeded by the flow capability of the integral valve means defined in claim
 6. 7. A fire nozzle comprising a nozzle body including a fluid conduit; a stem, one end of said stem being attached to said nozzle body and the other end being attached to a cylinder; a movable baffle-piston adapted to slide within said cylinder and along a section of said stem; orifice means in said baffle-piston providing a passageway for fluid to flow from said fluid conduit into said cylinder; hydraulic valve means adapted to permit fluid to flow out from said cylinder when the pressure within said cylinder tends to exceed predetermined pressure; said baffle-piston being so arranged that its position with respect to said nozzle body defines an annular opening which permits fluid to flow around said piston-baffle and out of said nozzle.
 8. A nozzle as defined by claim 7 wherein the size of said annular opening is controlled hydraulically. 